Moodle Home Page with Plain Text Only, no Theme

I have just finished my Moodle instalation, through command line, using SSH. It went smootly, without any errors, but now I face something I feel like its a huge problem. My moodle is using no theme, its plain text.

Any clues on how can I solve it?

Solved the problem, so I post it here expecting it can be usefull for others:

Simply, deactivate 'slash arguments' from Site Admin > Server > HTTP.

Thanks for your help Andrew, but it wasn't a CSS related problem.